Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AE3043B8BDB; Mon, 23 Mar 2026 16:29:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774283364; cv=none; b=lwu1nWFjtkBzebsM9t/Ond+FdPw6PNLfZN1aJYgz0I29jN6Zoemoiu7ALr1ZqwUHw/FR909QlNDKio2NyRt1cvezygCQVJF1D1VzWvoMEKmcqo+S5CXmW2m4PRy0prIHqXpuLDDO68oh9bNpSFeizWgpGwZJoGSYY8lLAe0Lx0w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774283364; c=relaxed/simple; bh=QV1VzUubAT43jrPpkG6mle9g0+b3wQdRQqWPiiQNZCw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Bv82yCOMa5tyxvvMvpLgEHBS/W0sn0+PEVwCZ64T1ISVUO3iGOe8ldeZyK+y53r4+TA4onsEN24jmDxrdYTq3Vnbc6Ux1Sxhwt+VsMs/pIlzsnCwQwjrBIF9aqhClFsCjycVrDldjmXuN1yObjq1AaJM8YOzMZNR5p+O0yV/3F0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=C2UPPJVQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="C2UPPJVQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E851CC2BC9E; Mon, 23 Mar 2026 16:29:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774283364; bh=QV1VzUubAT43jrPpkG6mle9g0+b3wQdRQqWPiiQNZCw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C2UPPJVQLDO7cGqwsLMuc3Bd+ux1iFFLbULksvHylu92/ddvqitcFFs/JAwQUjbs2 nbmdlS4f4MlkcruV9nLKaId+bAWoT5R9K1CF2utOM75RhQFffSph3Y27+XQd7fWcxL Cj6TT8wR9BM7WCK77wFA4wU/rDNz1nvCY4SIYoSg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daeho Jeong , Chao Yu , Jaegeuk Kim , Rahul Sharma Subject: [PATCH 6.1 469/481] f2fs: fix to trigger foreground gc during f2fs_map_blocks() in lfs mode Date: Mon, 23 Mar 2026 14:47:31 +0100 Message-ID: <20260323134536.648404669@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260323134525.256603107@linuxfoundation.org> References: <20260323134525.256603107@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chao Yu [ Upstream commit 1005a3ca28e90c7a64fa43023f866b960a60f791 ] w/ "mode=lfs" mount option, generic/299 will cause system panic as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:2835! Call Trace: f2fs_allocate_data_block+0x6f4/0xc50 f2fs_map_blocks+0x970/0x1550 f2fs_iomap_begin+0xb2/0x1e0 iomap_iter+0x1d6/0x430 __iomap_dio_rw+0x208/0x9a0 f2fs_file_write_iter+0x6b3/0xfa0 aio_write+0x15d/0x2e0 io_submit_one+0x55e/0xab0 __x64_sys_io_submit+0xa5/0x230 do_syscall_64+0x84/0x2f0 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0010:new_curseg+0x70f/0x720 The root cause of we run out-of-space is: in f2fs_map_blocks(), f2fs may trigger foreground gc only if it allocates any physical block, it will be a little bit later when there is multiple threads writing data w/ aio/dio/bufio method in parallel, since we always use OPU in lfs mode, so f2fs_map_blocks() does block allocations aggressively. In order to fix this issue, let's give a chance to trigger foreground gc in prior to block allocation in f2fs_map_blocks(). Fixes: 36abef4e796d ("f2fs: introduce mode=lfs mount option") Cc: Daeho Jeong Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim [ The context change is due to the commit 2f51ade9524c ("f2fs: f2fs_do_map_lock") in v6.3 which is irrelevant to the logic of this patch. ] Signed-off-by: Rahul Sharma Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/data.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1537,8 +1537,11 @@ int f2fs_map_blocks(struct inode *inode, end = pgofs + maxblocks; next_dnode: - if (map->m_may_create) + if (map->m_may_create) { + if (f2fs_lfs_mode(sbi)) + f2fs_balance_fs(sbi, true); f2fs_do_map_lock(sbi, flag, true); + } /* When reading holes, we need its node page */ set_new_dnode(&dn, inode, NULL, NULL, 0);